Alellopathic effects of aqueous extracts from Bambusa vulgaris Schrad. Ex J. C. Wendl. on seed germination and vigor from Lactuca sativa

The aim of this work was to evaluate allelopathic effects of aqueous extracts from Bambusa vulgaris leaves and culm on Lactuca sativa L. germination. Plant material was collected at Dois Irmãos State Park in Recife, Brazil, and analysis was performed at Laboratory of Forest Seeds Analysis at Rural Federal University of Pernambuco. Experiments were conducted under natural conditions using leaf and culm extracts at concentrations of 100, 75, 50 and 25%, using distilled water as control. Seed germination was evaluated for seven days. Percentage of germination (%G), speed index of germination (SIG), mean time of germination (MTG), and mean speed of germination (v) were determined. Aqueous extract of B. vulgaris leaves negatively influenced percentage of germination and speed of germination index of L. sativa seeds. Control treatment showed the best means, being statistically superior than other treatments that did not differ among each other. Considering L. sativa as a bioindicator, it is possible that allelopathic effects might significantly interfere on other species establishment and germination. This is due to substances present on plant residues deposited or incorporated to the soil annually. Finally, the inhibitory allelopathic behaviour of the germination process of L. sativa seeds in response to aqueous extracts of B. vulgaris was observed in all parts and concentrations tested. Key words: Allelopathy, allelochemicals, culm, bioindicator, Lactuca sativa, Bambusa vulgaris.